LinkedList.cpp

#include "LinkedList.h"
#include <iostream>
using namespace std;

LinkedList::LinkedList() {
   this->name = "";
   this->first = nullptr;
   this->last = nullptr;
   this->numNodes = 0; //no-arg. starts with no nodes
   
}

LinkedList::LinkedList(string word) {
   this->name = "";
   this->first = new Node(word);
   this->last = first;
   this->numNodes = 1; //starts with one node
   
}

LinkedList::~LinkedList() {
   this->clear();
}

Node* LinkedList::getFirst() const {
   return this->first;
}

Node* LinkedList::getLast() const {
   return this->last;
}

void LinkedList::setFirst(Node* newFirst) {
   this->first = newFirst;
}

void LinkedList::setLast(Node* newLast) {
   this->last = newLast;
}

string LinkedList::getNodeData(Node* node) const {
   string temp = "";
   if (node != nullptr) {
      temp = node->getData();
   }
   return temp; //returns blank string if nullptr
}

void LinkedList::setNodeData(Node* node, const string& newData) {
   if (node != nullptr) {
      node->setData(newData);
   }
}

string LinkedList::getName() const {
   return this->name;
}

void LinkedList::setName(const string& newName) {
   this->name = newName;
}

void LinkedList::push_back(const string& pushedData) {
   Node* temp = new Node(pushedData);
   
   if (first == nullptr) { //if list empty
      this->first = temp;
      this->last = temp; //make new node the only node in list
   } else {
      this->last->setNext(temp); //temp becomes new last node
      temp->setPrev(last); //last becomes 2nd last node
      this->last = temp; //make last point to new last node (temp)
   }
   
   ++this->numNodes;
}

void LinkedList::push_front(const string& pushedData) {
   Node* temp = new Node(pushedData);
   
   if (first == nullptr) { //if list empty
      this->first = temp;
      this->last = temp; //make new node the only node in list
   } else {
      this->first->setPrev(temp); //temp becomes new first node
      temp->setNext(first); //first becomes 2nd first node
      this->first = temp; //make last point to new first node (temp)
   }
   
   ++this->numNodes;
}

void LinkedList::insert(const string& pushedData, Node* current) {
   Node* toInsert = new Node(pushedData);
   
   if (first == nullptr) { //if list empty
      this->first = toInsert;
      this->last = toInsert; //make new node the only node in list
   } else {
      Node* prevNode = current->getPrev(); //stores node that comes before pushedData
      current->setPrev(toInsert); //current node linked to new node
      toInsert->setNext(current); //new node linked to current node
      toInsert->setPrev(prevNode); //new node linked to previous node
      prevNode->setNext(toInsert); //previous node linked to new node
   }
   
   ++this->numNodes;
}

void LinkedList::print() const {
   Node* temp = this->first;
   
   while (temp != nullptr) {
      cout << temp->getData() << endl;
      temp = temp->getNext(); //move to next node
   }
}

void LinkedList::print_reverse() const {
   Node* temp = this->last;
   
   while (temp != nullptr) {
      cout << temp->getData() << endl;
      temp = temp->getPrev(); //move to previous node
   }
}

int LinkedList::size() const {
   return this->numNodes;
}

void LinkedList::setSize(int newSize) {
   this->numNodes = newSize;
}

void LinkedList::clear() {
   Node* current = this->first;
   Node* temp;
   
   while (current != nullptr) { //iterate through list;
      temp = current;
      current = current->getNext(); //move pointer to next node
      delete temp; //delete node
   } //current should end as nullptr
   
   //deallocate private members
   this->first = nullptr;
   this->last = nullptr;
   this->name = "";
   this->numNodes = 0;
}